A device of the kind described above is known from the MBE-Review, no. 2, March 1990, published by VG Semicon Limited. The known device is used in systems for depositing materials, such as, for example, superconducting materials, in the form of thin layers on substrates. In such systems, a substrate is consecutively exposed to different material flows, each of which is derived from a source of material which is active continuously during a certain time. A predetermined thickness and composition of the thin layers can be obtained since the material flows are each periodically interrupted by a shutter. In the known device, the shutter is displaceable by means of a pneumatic drive unit which is situated outside the deposition chamber of the system, which is in a vacuum condition, in a system as described above.
A disadvantage of the known device is that for each displacement of the shutter the drive unit has to supply a quanity of energy required for the displacement which is to be provided from the exterior. In addition, unequal and inaccurate layer thicknesses are created in the deposition of layers having a thickness of only a few atom diameters, for which very short deposition times are used, because the time required for a displacement of the known shutter is too great in relation to the deposition time used owing to the mass inertia in the drive unit.